Abstract:
:After having been hunted to near-extinction in the Pacific maritime fur trade, the sea otter population at Amchitka Island, Alaska increased from very low numbers in the early 1900s to near equilibrium density by the 1940s. The population persisted at or near equilibrium through the 1980s, but declined sharply in the 1990s in apparent response to increased killer whale predation. Sea otter diet and foraging behavior were studied at Amchitka from August 1992 to March 1994 and the data compared with similar information obtained during several earlier periods. In contrast with dietary patterns in the 1960s and 1970s, when the sea otter population was at or near equilibrium density and kelp-forest fishes were the dietary mainstay, these fishes were rarely eaten in the 1990s. Benthic invertebrates, particularly sea urchins, dominated the otter's diet from early summer to mid-winter, then decreased in importance during late winter and spring when numerous Pacific smooth lumpsuckers (a large and easily captured oceanic fish) were eaten. The occurrence of spawning lumpsuckers in coastal waters apparently is episodic on a scale of years to decades. The otters' recent dietary shift away from kelp-forest fishes is probably a response to the increased availability of lumpsuckers and sea urchins (both high-preference prey). Additionally, increased urchin densities have reduced kelp beds, thus further reducing the availability of kelp-forest fishes. Our findings suggest that dietary patterns reflect changes in population status and show how an ecosystem normally under top-down control and limited by coastal zone processes can be significantly perturbed by exogenous events.
journal_name
Oecologiajournal_title
Oecologiaauthors
Watt J,Siniff DB,Estes JAdoi
10.1007/s004420000373subject
Has Abstractpub_date
2000-08-01 00:00:00pages
289-298issue
2eissn
0029-8549issn
1432-1939pii
10.1007/s004420000373journal_volume
124pub_type
杂志文章相关文献
OECOLOGIA文献大全abstract::Spatial and temporal niche differentiation are potential mechanisms of plant species' coexistence in many communities, including many grasslands. In a 6-year field experiment, a dominant prairie bunchgrass, Schizachyrium scoparium, excluded species sharing similar phenology and rooting depth, but coexisted with specie...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-005-0010-y
更新日期:2005-05-01 00:00:00
abstract::Exposure to enhanced levels of ambient ultraviolet (UV) radiation (UVR) can have adverse effects on aquatic organisms including damage at the cellular and molecular level and impairment of development, fecundity and survival. Much research has been conducted on the role of the harmful UVB radiation. However, due to it...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-013-2773-x
更新日期:2014-02-01 00:00:00
abstract::The thermoregulatory significance of a striped-melanic colour polymorphism in the common garter snake, Thamnophis sirtalis, was assessed through a combination of labortory experimentation and field study. In experiments with living snakes the melanic morph maintained a higher body temperature than the striped morph, w...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00346675
更新日期:1979-10-01 00:00:00
abstract::Diapause allows insects to temporally avoid conditions that are unfavorable for development and reproduction. However, diapause may incur a cost in the form of reduced metabolic energy reserves, reduced potential fecundity, and missed reproductive opportunities. This study investigated a hitherto ignored consequence o...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-006-0428-x
更新日期:2006-08-01 00:00:00
abstract::We used Y-plant, a computer-based model of crown architecture, to examine the implications of leaf reorientation resulting from petiole bending in Psychotria limonensis (Rubiaceae) seedlings. During this reorientation process, bending of the petioles of lower leaves that are potentially self-shaded by the upper leaves...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-002-1158-3
更新日期:2003-03-01 00:00:00
abstract::The growth of metacommunity ecology as a subdiscipline has increased interest in how processes at different spatial scales structure communities. However, there is still a significant knowledge gap with respect to relating the action of niche- and dispersal-assembly mechanisms to observed species distributions across ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-008-1141-8
更新日期:2008-11-01 00:00:00
abstract::Myrmecophytic symbioses are widespread in tropical ecosystems and their diversity makes them useful tools for understanding the origin and evolution of mutualisms. Obligate ant-plants, or myrmecophytes, provide a nesting place, and, often, food to a limited number of plant-ant species. In exchange, plant-ants protect ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-010-1739-5
更新日期:2011-02-01 00:00:00
abstract::Inter-specific competition, facilitation and predation influence herbivore assemblages, but no study has experimentally explored the interactions between large ungulates and small rodents. In a fully replicated, landscape scale experiment, we manipulated densities of domestic sheep in mountain pastures in Norway. We t...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-004-1792-z
更新日期:2005-04-01 00:00:00
abstract::Most research on the demography of wild animal populations has focused on characterizing the variation in the mortality of organisms as a function of intrinsic and environmental characteristics. However, such variation in mortality is difficult to relate to functional life history components (e.g. reproduction, disper...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-016-3597-2
更新日期:2016-07-01 00:00:00
abstract::Interrelationships between morphology, microhabitat, water relations, and photosynthesis of a xeric fern, Notholaena parryi D.C. Eat. (Pteridaceae), were examined in the western Colorado desert. In its typical microhabitat rock outcroppings protected N. parryi from direct sunlight and moderated the diurnal variations ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00346249
更新日期:1978-01-01 00:00:00
abstract::A series of field and laboratory experiments were conducted to examine whether natural levels of insect herbivory affect the arbuscular mycorrhizal (AM) colonization of two plant species. The plant species were the highly mycorrhizal (mycotrophic) Plantago lanceolata, which suffers small amounts of insect damage conti...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-001-0863-7
更新日期:2002-03-01 00:00:00
abstract::The life ofOncopeltus fasciatus centers on the seeds of milkweeds (Asclepiadaceae,Asclepias syriaca in this study). Adults reproduce prolifically on these seeds, but they engage in only half as much copulation and lay only a few eggs when fed milkweed buds and flowers instead. They can not maintain body weight on a di...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00582894
更新日期:1976-06-01 00:00:00
abstract::Competition between larvae of two anuran species (Bufo bufo and B. calamita) was investigated under field conditions likely to disfavour cell-mediated interference mechanisms. The experiment used triplicated cage treatments in an unshaded farm pond, a poor habitat for the unicellular pathogen Anurofeca richardsi impli...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050022
更新日期:2000-07-01 00:00:00
abstract::Masting is the intermittent production of large seed crops by a population of plants. Two main hypotheses have been proposed to explain masting. Variations in seed crop may result from stochastic climate factors (temperature, rainfall, etc.), and/or masting may be a plant evolutionary strategy to avoid specific seed p...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-008-1233-5
更新日期:2009-03-01 00:00:00
abstract::The impacts of disturbance on biodiversity and distributions have been studied in many systems. Yet, comparatively less is known about how lichens-obligate symbiotic organisms-respond to disturbance. Successful establishment and development of lichens require a minimum of two compatible yet usually unrelated species t...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-019-04413-0
更新日期:2019-06-01 00:00:00
abstract::Despite many studies highlighting the widespread occurrence and effects of resource movement between ecosystems, comparatively little is known about how anthropogenic alterations to ecosystems affect the strength, direction and importance of such fluxes. Hydrological regime and riparian land use cause well-documented ...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-015-3462-8
更新日期:2016-02-01 00:00:00
abstract::In the non-reproductive period, six species of brood parasites (4 cuckoos, 2 viduines) observed in Rhodesia and in the Kalahari were found to inhabit other areas than their hosts, being either nomadic or migratory in habit. They are hence exposed to different environmental conditions.Histological examination of the go...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00390385
更新日期:1969-09-01 00:00:00
abstract::Climate change is disrupting species interactions by altering the timing of phenological events such as budburst for plants and hatching for insects. We combined field observations with laboratory manipulations to investigate the consequences of climate warming on the phenology and performance of the eastern tent cate...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-015-3371-x
更新日期:2015-11-01 00:00:00
abstract::There is growing recognition that changes in vegetation composition can strongly influence peatland carbon cycling, with potential feedbacks to future climate. Nevertheless, despite accelerated climate and vegetation change in this ecosystem, the growth responses of peatland plant species to combined warming and veget...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-015-3254-1
更新日期:2015-05-01 00:00:00
abstract::Large-bodied zooplankton of the genus Daphnia are thought to be keystone species in freshwater pelagic habitats, potentially able to exert strong grazing effects and enhance phosphorus limitation of algae. I examined the degree to which Daphnia pulex differ from small-bodied zooplankton in their effects on algal bioma...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-002-0934-4
更新日期:2002-05-01 00:00:00
abstract::Spontaneous bleeding of sugar-rich sap from cambial-deep incisions in the bark of trunks was demonstrated for Eucalyptus globulus and other eucalypts across a range of localities and seasonal conditions in south-west Australia. High levels of sucrose and raffinose (up to 31% w/v total sugars) were present in the exuda...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420050664
更新日期:1998-12-01 00:00:00
abstract::Prescribed burning is a major control over element cycles in Tallgrass prairie (Eastern Kansas, USA). In this paper we report potential effects of fire on nonsymbiotic nitrogen fixation. Fire resulted in additions of available P in ash, which may stimulate nitrogen fixation by terrestrial cyanobacteria. Cyanobacterial...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00378663
更新日期:1989-06-01 00:00:00
abstract::Several studies published over the last years suggest that the ability of many species to cope with global change will be closely related to the current amount of plasticity for fitness-related traits. Thus, disentangling general patterns in phenotypic flexibility, which could be then included in models aimed to predi...
journal_title:Oecologia
pub_type: 杂志文章,meta分析
doi:10.1007/s00442-013-2682-z
更新日期:2013-11-01 00:00:00
abstract::1. It was clarified, by means of breeding experiments conducted within a temperature range of 14-34°C, if the growth of Pieris influenced by diurnally fluctuating temperatures depends on a simple additive influence of day-and-night-temperatures or if its growth is accelerated or retarded under these conditions by spec...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00369026
更新日期:1975-06-01 00:00:00
abstract::In tropical rain forests of Central America, the canopy tree Dipteryx panamensis (Papilionaceae) fruits when overall fruit biomass is low for mammals. Flying and arboreal consumers feed on D. panamensis and drop seeds under the parent or disperse them farther away. Seeds on the ground attract many vertebrate seed-eate...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00341325
更新日期:1993-05-01 00:00:00
abstract::Spatiotemporal variation in the interactions among plants and animals is widespread; yet our conceptual and empirical understanding of this variation is limited to a few types of visitors, mainly herbivores, pollinators, seed predators, and seed dispersers. Despite the ubiquity of nectar robbing and the strength of it...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s00442-002-1060-z
更新日期:2002-12-01 00:00:00
abstract::This study examines the impacts of woody, N2-fixing invasive Acacia spp. on the patterns of nutrient cycling in two invaded ecosystems of differing nutrient status in the Cape floristic region. Patterns of soil nutrient mineralization were measured by a field incubation method while the significance of the fixation pr...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00328825
更新日期:1995-03-01 00:00:00
abstract::Twenty nine harpacticoid copepods are new to Bermuda and significant changes are noted in the distribution records of several species. Six temporary groups are organized to separate the copepods on their apparent zoogeographical ranges: (1) cosmopolitan, (2) warm temperate-tropical, (3) North Atlantic, (4) North Atlan...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00815503
更新日期:1970-12-01 00:00:00
abstract::The physiological activity and C and N allocation of beech seedlings planted in two different beech forest soils (acid brown earth, rendzina) were studied over 80 days. One adult earthworm Octolasion lacteum (Örley) was placed in half of the containers. Transpiration, CO2, assimilation, chlorophyll synthesis and N inc...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/BF00328412
更新日期:1991-09-01 00:00:00
abstract::We compared the parasitoid communities associated with grass-feeding herbivores in Germany and Britain to examine geographical consistency in community composition and to test ecological characteristics of the plants and host insects that may explain variability in parasitoid community structure. The parasitoid commun...
journal_title:Oecologia
pub_type: 杂志文章
doi:10.1007/s004420100733
更新日期:2001-11-01 00:00:00